The present invention relates to low-loss sampling and especially a device for low-loss sampling.
A sampling valve is known from EP-A-350 723 with a casing mounted on a container or line. The casing has an axial bore inside of which a valve stem is movably maintained. In one embodiment, the valve stem has a longitudinal bore, which, adjacent to its unattached end, opens into a continuous cross bore. Placed on both sides of the cross bore are sealing rings in grooves on the valve stem. The stem is positionable into a first position in which the cross bore projects into the interior space of the container and into a second position, in which it is sealed. In the first position a sample can be extracted through the longitudinal bore.
This prior sampling valve can be cleaned and sterilized only together with the container or after dismantling. Automatic, periodic sampling during an ongoing process is not possible with this sampling valve.
Sampling is very common in sterile process technology (pharmaceutical engineering and bio-engineering).
Growing demands in production (process control, archiving of samples), as well as in process development, are promoting the development of new, improved systems. The products are becoming increasingly more expensive and the production volumes tend to become smaller. Furthermore, Modern analysis methods make it possible to use increasingly smaller samples. This has created a demand for increasingly smaller extracted quantities and a requirement to keep losses, including losses due to sampling, at a minimum, especially in the field of process development where there is a demand for regular sampling in the 24-hour operation. Another application in sterile production is the sampling from product-transporting lines.
The present invention is based on the objective of taking, under sterile conditions, a sample of a defined volume from a sterile tank or a sterile line of fluid. The objective is to take the sample, e.g. a defined volume from the fluid, either via a nozzle or an immersion pipe. This defined volume is to be ejected as completely as possible during a second step and transported to a removal location. This removal location could be a sterile packing drum or automatic sterile filling machine, which, for example, stores the samples refrigerated (autosampler), or it could be an automatic analysis machine (e.g., with sample processing, with gas chromatographs and with automatic processing of the measured values). In a third step, the system must be cleaned in place (CIP) and sterilized in place (SIP). The objective is to make this cycle reproducible and repeatable as often as desired without jeopardizing the sterile operation.